Controllable production well packer

ABSTRACT

The existence and rate of corrosion in a section of a well tubing or well casing is determined and monitored by installing at predetermined locations as the string is placed in the well bore, sections of pipe ( 20 ) that have been fitted with an array of piezoelectric transducers ( 26 ) and a microprocessor ( 28 ) that controls signals going to and from each array of transducers and signals going to and received from controls and intrumentation apparatus located at the earth&#39;s surface. The microprocessors at varying locations along the string are electrically connected to the surface control and instrumentation apparatus by conductor cables and/or by wireless means using the pipe string as the conductive path for electrical signals.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the benefit of the following U.S.Provisional Applications, all of which are hereby incorporated byreference: COMMONLY OWNED AND PREVIOUSLY FILED U.S. PROVISIONAL PATENTAPPLICATIONS T&K # Ser. No. Title Filing Date TH 1599 60/177,999Toroidal Choke Inductor for Jan. 24, 2000 Wireless Communication andControl TH 1600 60/178,000 Ferromagnetic Choke in Jan. 24, 2000 WellheadTH 1602 60/178,001 Controllable Gas-Lift Well Jan. 24, 2000 and Valve TH1603 60/177,883 Permanent, Downhole, Wire- Jan. 24, 2000 less, Two-WayTelemetry Backbone Using Redundant Repeater, Spread Spectrum Arrays TH1668 60/177,998 Petroleum Well Having Jan. 24, 2000 Downhole Sensors,Communication, and Power TH 1669 60/177,997 System and Method Jan. 24,2000 for Fluid Flow Optimization TS 6185 60/181,322 A Method andApparatus for Feb. 9, 2000 the Optimal Predistortion of anElectromagnetic Signal in a Downhole Communica- tions System TH 1599x60/186,376 Toroidal Choke Inductor for Mar. 2, 2000 WirelessCommunication and Control TH 1600x 60/186,380 Ferromagnetic Choke inMar. 2, 2000 Wellhead TH 1601 60/186,505 Reservoir Production ControlMar. 2, 2000 from Intelligent Well Data TH 1671 60/186,504 TracerInjection in a Pro- Mar. 2, 2000 duction Well TH 1672 60/186,379 OilwellCasing Electrical Mar. 2, 2000 Power Pick-Off Points TH 1673 60/186,394Controllable Production Mar. 2, 2000 Well Packer TH 1674 60/186,382 Useof Downhole High Mar. 2, 2000 Pressure Gas in a Gas Lift Well TH 167560/186,503 Wireless Smart Well Casing Mar. 2, 2000 TH 1677 60/186,527Method for Downhole Power Mar. 2, 2000 Management Using Energizationfrom Distributed Batteries or Capacitors with Reconfigurable DischargeTH 1679 60/186,393 Wireless Downhole Well Mar. 2, 2000 Interval Inflowand Injection Control TH 1681 60/186,394 Focused Through-Casing Mar. 2,2000 Resistivity Measurement TH 1704 60/186,531 Downhole RotaryHydraulic Mar. 2, 2000 Pressure for Valve Actuation TH 1705 60/186,377Wireless Downhole Measure- Mar. 2, 2000 ment and Control For OptimizingGas Lift Well and Field Performance TH 1722 60/186,381 ControlledDownhole Mar. 2, 2000 Chemical Injection TH 1723 60/186,378 WirelessPower and Mar. 2, 2000 Communications Cross-Bar Switch

[0002] The current application shares some specification and figureswith the following commonly owned and concurrently filed applications,all of which are hereby incorporated by reference: COMMONLY OWNED ANDCONCURRENTLY FILED U.S PATENT APPLICATIONS Filing T&K # Ser. No. TitleDate TH 1601US 09/                     Reservoir Production Control fromIntelligent Well Data TH 1671US 09/                     Tracer Injectionin a Production Well TH 1672US 09/                     Oil Well CasingElectrical Power Pick-Off Points TH 1674US 09/                     Useof Downhole High Pressure Gas in a Gas-Lift Well TH 1675US09/                     Wireless Smart Well Casing TH 1677US09/                     Method for Downhole Power Management UsingEnergization from Distributed Batteries or Capacitors withReconfigurable Discharge TH 1679US 09/                     WirelessDownhole Well Interval Inflow and Injection Control TH 1681US09/                     Focused Through-Casing Resistivity MeasurementTH 1704US 09/                     Downhole Rotary Hydraulic Pressure forValve Actuation TH 1705US 09/                     Wireless DownholeMeasure- ment and Control For Optimizing Gas Lift Well and FieldPerformance TN 1722US 09/                     Controlled DownholeChemical Injection TH 1723US 09/                     Wireless Power andCommunications Cross-Bar Switch

[0003] The current application shares some specification and figureswith the following commonly owned and previously filed applications, allof which are hereby incorporated by reference: COMMONLY OWNED ANDPREVIOUSLY FILED U.S PATENT APPLICATIONS Filing T&K # Ser. No. TitleDate TH 1599US 09/                     Choke Inductor for WirelessCommunication and Control TH 1600US 09/                     InductionChoke for Power Distribution in Piping Structure TH 1602US09/                     Controllable Gas-Lift Well and Valve TH 1603US09/                     Permanent Downhole, Wireless, Two-Way TelemetryBackbone Using Redundant Repeater TH 1668US 09/                    Petroleum Well Having Down- hole Sensors, Communication, and Power TH1669US 09/                     System and Method for Fluid FlowOptimization TH 1783US 09/                     Downhole Motorized FlowControl Valve TS 6185US 09/                     A Method and Apparatusfor the Optimal Predistortion of an Electro Magnetic Signal in aDownhole Communications System

[0004] The benefit of 35 U.S.C. § 120 is claimed for all of the abovereferenced commonly owned applications. The applications referenced inthe tables above are referred to herein as the “Related Applications.”

BACKGROUND OF THE INVENTION

[0005] 1. Field of the Invention

[0006] The present invention relates to a controllable production wellpacker. In one aspect, it relates to a petroleum production well packercomprising an electrically powered device, in which the device maycomprise an electrically controllable valve, a communications andcontrol module, a sensor, a modem, a tracer injection module, or anycombination thereof.

[0007] 2. Description of the Related Art

[0008] Petroleum wells (e.g., oil and/or gas wells) typically passthrough formations containing multiple zones that may produce differingfluids, as well as impermeable zones. The fluid-bearing zones mayproduce saline or clear water, oil, gas, or a mixture of thesecomponents.

[0009] It is desirable and customary to maintain hydraulic isolationbetween zones so that the fluids produced from each zone may be receivedseparately at the surface. Even if a particular zone is not producingpetroleum products, it is usually necessary to ensure that fluids fromthat zone do not travel to other zones using the wellbore as a transportpath, and to avoid contamination of the fluids in each zone.

[0010] The necessary isolation between zones is often provided bypackers. A typical hydraulically set production packer of the prior artis schematically shown in FIG. 1. Packers are mechanical devices thatclose the annulus between the production tubing and the casing, and sealto both. Packers are typically installed at the time of well. completionby attaching them to a tubing string as it is lowered into the well.Thus, during placement, the packer must pass freely within the casing.Once it is in place, a hydraulic actuator (energized and controlled fromthe surface) operates the sealing mechanism of the packer, which clampsthe packer to the casing and effects a fluid-tight seal in the annularspace between the tubing and the casing.

[0011] Packers may provide complete isolation between the annular spacesabove and below them, or may be equipped with one or more presetmechanically-actuated valves to control flow past them. When controlvalves are included, however, their settings can only be altered bymechanically inserting a slick-line tool, which is inconvenient, slow,and relatively costly. Additionally, when there are multiple zones andmultiple packers it is often impossible or impractical to reach thelowermost packers with a slick-line tool. This lack of a fast andinexpensive method for controlling valves in a packer is a constraint onwell design and production operations.

[0012] Conventional packers are known such as described in U.S. Pat.Nos. 6,148,915, 6,123,148, 3,566,963 and 3,602,305.

[0013] All references cited herein are incorporated by reference to themaximum extent allowable by law. To the extent a reference may not befully incorporated herein, it is incorporated by reference forbackground purposes, and indicative of the knowledge of one of ordinaryskill in the art.

BRIEF SUMMARY OF THE INVENTION

[0014] The problems and needs outlined above are largely solved and metby the present invention. In accordance with one aspect of the presentinvention, a packer adapted for use in a petroleum well, wherein thepacker comprises an electrically powered device, is provided. Theelectrically powered device may comprise an electrically controllablevalve adapted to control fluid communication from one side of the packerto another side of the packer when the packer is operably installed. Theelectrically powered device may further comprise a communications andcontrol module being electrically connected to the electricallycontrollable valve, wherein the module comprises a modem adapted toreceive control commands encoded within communication signals. Themodule can be adapted to decode the control commands received by themodem and control the movement of the valve using the control commandswhen the packer is operably installed. Alternatively, the electricallypowered device may comprise a sensor adapted to detect at least onephysical characteristic of a surrounding environment and generate datacorresponding to the physical characteristic, as well as a modem adaptedto receive the data from the sensor and electrically transmit the datain the form of an electrical communication signal. Hence, theelectrically powered device can comprise an electrically controllablevalve, a sensor, a modem, a communications and control module, a tracerinjection module, or any combination thereof.

[0015] In accordance with another aspect of the present invention, apetroleum production well incorporating the packer described above isprovided. The petroleum well comprises a piping structure, a source oftime-varying current, an electrical return, an induction choke, and thepacker. The piping structure of the well comprises an electricallyconductive portion extending along at least part of the pipingstructure. The piping structure can comprise a production tubing stringof the well. The source of time-varying current comprises two sourceterminals. A first of the source terminals is electrically connected tothe electrically conductive portion of the piping structure. Theelectrical return electrically connects between the electricallyconductive portion of the piping structure and a second of the sourceterminals of the time-varying current source. The electrical return cancomprise a well casing of the well, part of the packer, another packer,and/or a conductive fluid within the well. The induction choke islocated about part of the electrically conductive portion of the pipingstructure at a location along the piping structure between theelectrical connection location for the first source terminal and theelectrical connection location for the electrical return, such that avoltage potential is formed between the electrically conductive portionof the piping structure on a source-side of the induction choke, and theelectrically conductive portion of the piping structure on anelectrical-return-side of the induction choke as well as the electricalreturn when time-varying current flows through the electricallyconductive portion of the piping structure. The induction choke cancomprise a ferromagnetic material. Also, the induction choke need not bepowered when its size, geometry, and magnetic properties can providesufficient magnetic inductance for developing the voltage potentialdesired. The electrically powered device of the packer is electricallyconnected across the voltage potential such that part of thetime-varying current is routed through the device due to the inductionchoke when the time-varying current flows through the electricallyconductive portion of the piping structure.

[0016] In accordance with yet another aspect of the present invention, amethod of producing petroleum products from a petroleum well comprisingan electrically powered packer is provided.

[0017] A conventional petroleum well includes a cased wellbore having atubing string positioned within and longitudinally extending within thecasing. In a preferred embodiment, a controllable packer is coupled tothe tubing to provide a seal of the annular space between the tubing andcasing. A valve in the packer (and/or other devices, such as sensors) ispowered and controlled from the surface. Communication signals and powerare sent from the surface using the tubing and casing as conductors. Atleast one induction choke is coupled about the tubing downhole tomagnetically inhibit alternating current flow through the tubing at achoke. An insulating tubing joint, another induction choke, or anotherinsulating means between the tubing and casing can be located at thesurface above a location where current and communication signals areimparted to the tubing. Hence, most of the alternating current iscontained between the downhole choke and the insulating tubing joint, orbetween the chokes when two chokes are used.

[0018] The Related Applications describe alternative ways to provideelectrical power from the surface to downhole modules, and to establishbidirectional communications for data and commands to be passed betweenthe surface and downhole modules using surface and downhole modems. Apreferred embodiment utilizes the production tubing and the well casingas the electrical conduction path between the surface and downholeequipment. The cost reduction and simplification of installationprocedures which accrue from obviating the need for electrical cables toprovide power, sensing, and control functions downhole allow widerdeployment of active equipment downhole during production.

[0019] In the context of downhole packers, the ability to power andcommunicate with the packer has many advantages. Such a controllablepacker in accordance with the present invention may incorporate sensors,with data from the sensors being received in real time at the surface.Similarly, the availability of power downhole, and the ability to passcommands from the surface to the controllable packer, allow electricallymotorized mechanical components, such as flow control valves, to beincluded in packer design, thus increasing their flexibility in use.Notably, the control of such components in the controllable packerhereof is near real time, allowing packer flow control valves to beopened, closed, adjusted, or throttled constantly to contribute to themanagement of production.

[0020] In a preferred embodiment, a surface computer having a mastermodem can impart a communication signal to the tubing, and thecommunication signal is received at a slave modem downhole, which iselectrically connected to or within the controllable packer. Thecommunication signal can be received by the slave modem either directlyor indirectly via one or more relay modems. Further, electric power canbe input into the tubing string and received downhole to power theoperation of sensors or other devices in the controllable packer.Preferably, the casing is used as a conductor for the electrical return.

[0021] In a preferred embodiment, a controllable valve in the packerregulates the fluid communication in the annulus between the casing andtubing. The electrical return path can be provided along part of thecontrollable packer, and preferably by the expansion of the expansionslips into contact with the casing. Alternatively, the electrical returnpath may be via a conductive centralizer around the tubing which isinsulated in its contact with the tubing, but is in electrical contactwith the casing and electrically connected to the device in the packer.

[0022] In enhanced forms, the controllable packer includes one or moresensors downhole which are preferably in contact with the downhole modemand communicate with the surface computer via the tubing and/or wellcasing. Such sensors as temperature, pressure, acoustic, valve position,flow rates, and differential pressure gauges can be advantageously usedin many situations. The sensors supply measurements to the modem fortransmission to the surface or directly to a programmable interfacecontroller operating a downhole device, such as controllable valve forcontrolling the fluid flow through the packer.

[0023] In one embodiment, ferromagnetic induction chokes are coupledabout the tubing to act as a series impedance to current flow on thetubing. In a preferred form, an upper ferromagnetic choke. is placedaround the tubing below the casing hanger, and the current andcommunication signals are imparted to the tubing below the upperferromagnetic choke. A lower ferromagnetic choke is placed downholearound the tubing with the controllable packer electrically coupled tothe tubing above the lower ferromagnetic choke, although thecontrollable packer may be mechanically coupled to the tubing below thelower ferromagnetic choke instead.

[0024] Preferably, a surface computer is coupled via a surface mastermodem and the tubing to the downhole slave modem of the controllablepacker. The surface computer can receive measurements from a variety ofsources (e.g., downhole sensors), measurements of the oil output fromthe well, and measurements of the compressed gas input to the well inthe case of a gas lift well. Using such measurements, the computer cancompute desired positions of the controllable valve in the packer, andmore particularly, the optimum amount of fluid communication to permitinto the annulus inside the casing.

[0025] Construction of such a petroleum well is designed to be assimilar to conventional construction methodology as possible. That is,after casing the well, a packer is typically set to isolate each zone.In a production well, there may be several oil producing zones, waterproducing zones, impermeable zones, and thief zones. It is desirable toprevent or permit communication between the zones. For example whenimplementing the present invention, the tubing string is fed through thecasing into communication with the production zone, with controllablepackers defining the production zone. As the tubing string is made up atthe surface, a lower ferromagnetic choke is placed around one of theconventional tubing strings for positioning above the lowermostcontrollable packer. In the sections of the tubing strings where it isdesired, another packer is coupled to the tubing string to isolatezones. Controllable gas lift valves or sensor pods also may be coupledto the tubing as desired by insertion in a side pocket mandrel (tubingconveyed) and corresponding induction chokes as needed. The tubingstring is made up to the surface where an upper ferromagnetic inductionchoke is again placed around the tubing string below the casing hanger.Communication and power leads are then connected to the tubing stringbelow the upper choke. In an enhanced form, an electrically insulatingjoint is used instead of the upper induction choke.

[0026] A sensor and communication pod can be incorporated into thecontrollable packer of the present invention without the necessity ofincluding a controllable valve or other control device. That is, anelectronics module having pressure, temperature or acoustic sensors,power supply, and a modem can be incorporated into the packer forcommunication to the surface computer using the tubing and casing asconductors.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other objects and advantages of the invention will becomeapparent upon reading the following detailed description and uponreferencing the accompanying drawings, in which:

[0028]FIG. 1 is a schematic showing a typical packer of the prior art;

[0029]FIG. 2 is a schematic showing a petroleum production well inaccordance with a preferred embodiment of the present invention;

[0030]FIG. 3 is a simplified electrical schematic of the embodimentshown in FIG. 2; and

[0031]FIG. 4 is an enlarged schematic showing a controllable packer,from FIG. 2, comprising an electrically controllable valve.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Referring now to the drawings, wherein like reference numbers areused herein to designate like elements throughout the various views, apreferred embodiment of the present invention is illustrated and furtherdescribed, and other possible embodiments of the present invention aredescribed. The figures are not necessarily drawn to scale, and in someinstances the drawings have been exaggerated and/or simplified in placesfor illustrative purposes only. One of ordinary skill in the art willappreciate the many possible applications and variations of the presentinvention based on the following examples of possible embodiments of thepresent invention, as well as based on those embodiments illustrated anddiscussed in the Related Applications, which are incorporated byreference herein to the maximum extent allowed by law.

[0033] As used in the present application, a “piping structure” can beone single pipe, a tubing string, a well casing, a pumping rod, a seriesof interconnected pipes, rods, rails, trusses, lattices, supports, abranch or lateral extension of a well, a network of interconnectedpipes, or other similar structures known to one of ordinary skill in theart. The preferred embodiment makes use of the invention in the contextof a petroleum well where the piping structure comprises tubular,metallic, electrically-conductive pipe or tubing strings, but theinvention is not so limited. For the present invention, at least aportion of the piping structure needs to be electrically conductive,such electrically conductive portion may be the entire piping structure(e.g., steel pipes, copper pipes) or a longitudinal extendingelectrically conductive portion combined with a longitudinally extendingnon-conductive portion. In other words, an electrically conductivepiping structure is one that provides an electrical conducting path froma first portion where a power source is electrically connected to asecond portion where a device and/or electrical return is electricallyconnected. The piping structure will typically be conventional roundmetal tubing, but the cross-section geometry of the piping structure, orany portion thereof, can vary in shape (e.g., round, rectangular,square, oval) and size (e.g., length, diameter, wall thickness) alongany portion of the piping structure. Hence, a piping structure must havean electrically conductive portion extending from a first portion of thepiping structure to a second portion of the piping structure, whereinthe first portion is distally spaced from the second portion along thepiping structure.

[0034] Note that the terms “first portion” and “second portion” as usedherein are each defined generally to call out a portion, section, orregion of a piping structure that may or may not extend along the pipingstructure, that can be located at any chosen place along the pipingstructure, and that may or may not encompass the most proximate ends ofthe piping structure.

[0035] Similarly, in accordance with conventional terminology ofoilfield practice, the descriptors “upper”, “lower”, “uphole” and“downhole” are relative and refer to distance along hole depth from thesurface, which in deviated or horizontal wells may or may not accordwith vertical elevation measured with respect to a survey datum.

[0036] Also note that the term “modem” is used herein to genericallyrefer to any communications device for transmitting and/or receivingelectrical communication signals via an electrical conductor (e.g.,metal). Hence, the term “modem” as used herein is not limited to theacronym for a modulator (device that converts a voice or data signalinto a form that can be transmitted)/demodulator (a device that recoversan original signal after it has modulated a high frequency carrier).Also, the term “modem” as used herein is not limited to conventionalcomputer modems that convert digital signals to analog signals and viceversa (e.g., to send digital data signals over the analog PublicSwitched Telephone Network). For example, if a sensor outputsmeasurements in an analog format, then such measurements may only needto be modulated (e.g., spread spectrum modulation) and transmitted—henceno analog/digital conversion needed. As another example, a relay/slavemodem or communication device may only need to identify, filter,amplify, and/or retransmit a signal received.

[0037] As used in the present application, “wireless” means the absenceof a conventional, insulated wire conductor e.g. extending from adownhole device to the surface. Using the tubing and/or casing as aconductor is considered “wireless.” The term “valve” as used hereingenerally refers to any device that functions to regulate the flow of afluid. Examples of valves include, but are not limited to, bellows-typegas-lift valves and controllable gas-lift valves, each of which may beused to regulate the flow of lift gas into a tubing string of a well.The internal workings of valves can vary greatly, and in the presentapplication, it is not intended to limit the valves described to anyparticular configuration, so long as the valve functions to regulateflow. Some of the various types of flow regulating mechanisms include,but are not limited to, ball valve configurations, needle valveconfigurations, gate valve configurations, and cage valveconfigurations. The methods of installation for valves discussed in thepresent application can vary widely.

[0038] The term “electrically controllable valve” as used hereingenerally refers to a “valve” (as just described) that can be opened,closed, adjusted, altered, or throttled continuously in response to anelectrical control signal (e.g., signal from a surface computer or froma downhole electronic controller module). The mechanism that actuallymoves the valve position can comprise, but is not limited to: anelectric motor; an electric servo; an electric solenoid; an electricswitch; a hydraulic actuator controlled by at least one electricalservo, electrical motor, electrical switch, electric solenoid, orcombinations thereof; a pneumatic actuator controlled by at least oneelectrical servo, electrical motor, electrical switch, electricsolenoid, or combinations thereof; or a spring biased device incombination with at least one electrical servo, electrical motor,electrical switch, electric solenoid, or combinations thereof. An“electrically controllable valve” may or may not include a positionfeedback sensor for providing a feedback signal corresponding to theactual position of the valve.

[0039] The term “sensor” as used herein refers to any device thatdetects, determines, monitors, records, or otherwise senses the absolutevalue of or a change in a physical quantity. A sensor as describedherein can be used to measure physical quantities including, but notlimited to: temperature, pressure (both absolute and differential), flowrate, seismic data, acoustic data, pH level, salinity levels, valvepositions, or almost any other physical data.

[0040]FIG. 1 is a schematic showing a conventional hydraulically setproduction packer 20 of the prior art set within a well casing 22 of awell. The packer 20 of FIG. 1 is threaded to a production tubing string24. The conventional packer 20 has a tail piece 26 that may terminatewith an open or closed end for the lowest packer in the completed well,or the tail piece 26 may be threaded onto tubing (not shown) that passesto lower regions of the well. The conventional packer 20 has a sectionof slips 28 and a seal section 30. Both the slips 28 and the sealsection 30 can pass freely inside the well casing 22 during placement,and are operated by a hydraulic actuator 32. When the packer 20 is atits final location in the casing 22, the hydraulic actuator 32 is usedto exert mechanical forces on the slips 28 and the seals 30 causing themto expand against the casing. The slips 28 lock the packer 20 in placeby gripping the internal surface of the casing 22 so that the packercannot be displaced by differential pressure between the spaces aboveand below the packer. The seal section 30 creates a liquid-tight sealbetween the spaces above and below the packer 20. The hydraulic actuator32 is operated using high-pressure oil supplied from the surface (notshown) by a control tube 34. However, the conventional packer 20 doesnot comprise an electrically powered device.

[0041]FIG. 2 is a schematic showing a petroleum production well 38 inaccordance with a preferred embodiment of the present invention. Thepetroleum production well 38 shown in FIG. 2 is similar to aconventional well in construction, but with the incorporation of thepresent invention. In this example, a packer 40 comprising anelectrically powered device 42 is placed in the well 38 in the samemanner as a conventional packer 20 would be—to separate zones in aformation. In the preferred embodiment, the electrically powered device42 of the packer 40 comprises an electrically controllable valve 44 thatacts as a bypass valve, as shown in more detail in FIG. 4 and describedfurther below.

[0042] In a preferred embodiment, the piping structure comprises part ofa production tubing string 24, and the electrical return comprises partof a well casing 22. An insulating tubing joint 146 and a ferromagneticinduction choke 48 are used in this preferred embodiment. The insulatingjoint 146 is incorporated close to the wellhead to electrically insulatethe lower sections of tubing 24 from casing 22. Thus, the insulatingjoint 146 prevents an electrical short-circuit between the lowersections of tubing 24 and casing 22 at the tubing hanger 46. The hanger46 provides mechanical coupling and support of the tubing 24 bytransferring the weight load of the tubing 24 to the casing 22. Theinduction choke 48 is attached about the tubing string 24 at a secondportion 52 downhole above the packer 40. A computer system 56 comprisinga master modem 58 and a source of time-varying current 60 iselectrically connected to the tubing string 24 below the insulatingtubing joint 146 by a first source terminal 61. The first sourceterminal 61 is insulated from the hanger 46 where it passes through it.A second source terminal 62 is electrically connected to the well casing22, either directly (as in FIG. 2) or via the hanger 46 (arrangement notshown). In alternative to or in addition to the insulating tubing joint146, another induction choke (not shown) can be placed about the tubing24 above the electrical connection location for the first sourceterminal 61 to the tubing.

[0043] The time-varying current source 60 provides the current, whichcarries power and communication signals downhole. The time-varyingcurrent is preferably alternating current (AC), but it can also be avarying direct current (DC). The communication signals can be generatedby the master modem 58 and embedded within the current produced by thesource 60. Preferably, the communication signal is a spread spectrumsignal, but other forms of modulation could be used in alternative.

[0044] The electrically powered device 42 in the packer 40 comprises twodevice terminals 71, 72, and there can be other device terminals asneeded for other embodiments or applications. A first device terminal 71is electrically connected to the tubing 24 on a source-side 81 of theinduction choke 48, which in this case is above the induction choke.Similarly, a second device terminal 72 is electrically connected to thetubing 24 on an electrical-return-side, 82 of the induction choke 48,which in this case is below the induction choke. In this preferredembodiment, the slips 28 of the packer 40 provide the electricalconnection between the tubing 24 and the well casing 22. However, aswill be clear to one of ordinary skill in the art, the electricalconnection between the tubing 24 and the well casing 22 can beaccomplished in numerous ways, some of which can be seen in the RelatedApplications, including (but not limited to): another packer(conventional or controllable); conductive fluid in the annulus betweenthe tubing and the well casing; a conductive centralizer; or anycombination thereof. Hence, an electrical circuit is formed using thetubing 24 and the well casing 22 as conductors to the downhole device 42within the packer 40.

[0045]FIG. 3 illustrates a simplified electrical schematic of theelectrical circuit formed in the well 38 of FIG. 2. The insulatingtubing joint 146 and the induction choke 48 effectively create anisolated section of the tubing string 24 to contain most of thetime-varying current between them. Accordingly, a voltage potentialdevelops between the isolated section of tubing 24 and the well casing22 when AC flows through the tubing string. Likewise, the voltagepotential also forms between tubing 24 on the source-side 81 of theinduction choke 48 and the tubing 24 on the electrical-return-side 82 ofthe induction choke 48 when AC flows through the tubing string. In thepreferred embodiment, the electrically powered device 42 in the packer40 is electrically connected across the voltage potential between thesource-side 81 and the electrical-return-side 82 of the tubing 24.However in alternative, the device 42 can be electrically connectedacross the voltage potential between the tubing 24 and the casing 22, orthe voltage potential between the tubing 24 and part of the packer 40(e.g., slips 28), if that part of the packer is electrically contactingthe well casing 22. Thus, part of the current that travels through thetubing 24 and casing 22 is routed through the device 42 due to theinduction choke 48.

[0046] As is made clear by consideration of the electrical equivalentcircuit diagram of FIG. 3, centralizers which are installed on thetubing between isolation device 47 and choke 48 must not provide anelectrically conductive path between tubing 24 and casing 22. Suitablecentralizers may be composed of solid molded or machined plastic, or maybe of the bow-spring type provided these are furnished with appropriateinsulating elements. Many suitable and alternative designimplementations of such centralizers will be clear to those of averageskill in the art.

[0047] Other alternative ways to develop an electrical circuit using apiping structure and at least one induction choke are described in theRelated Applications, many of which can be applied in conjunction withthe present invention to provide power and/or communications to theelectrically powered device 42 of the packer 40 and to form otherembodiments of the present invention.

[0048] Turning to FIG. 4, which shows more details of the packer 40 ofFIG. 2, it is seen that the controllable packer 40 is similar to theconventional packer 20 (shown in FIG. 1), but with the addition of anelectrically powered device 42 comprising an electrically controllablevalve 44 and a communications and control module 84. The communicationsand control module 84 is powered from and communicates with the computersystem 56 at the surface 54 via the tubing 24 and/or the casing 22. Thecommunications and control module 84 may comprise a modem 86, a powertransformer (not shown), a microprocessor (not shown), and/or othervarious electronic components (not shown) as needed for an embodiment.The communications and control module 84 receives electrical signalsfrom the computer system 56 at the surface 54 and decodes commands forcontrolling the electrically controlled valve 44, which acts as a bypassvalve. Using the decoded commands, the communications and control module84 controls a low current electric motor that actuates the movement ofthe bypass valve 44. Thus, the valve 44 can be opened, closed, adjusted,altered, or throttled continuously by the computer system 56 from thesurface 54 via the tubing 24 and well casing 22.

[0049] The bypass valve 44 of FIG. 4 controls flow through a bypass tube88, which connects inlet and outlet ports 90, 92 at the bottom and topof the packer 40. The ports 90, 92 communicate freely with the annularspaces 94, 96 (between the casing 22 and the tubing 24), above and belowthe packer 40. The bypass control valve 44 therefore controls fluidexchange between these spaces 94, 96, and this exchange may be alteredin real time using commands sent from the computer system 56 andreceived by the controllable packer 40.

[0050] The mechanical arrangement of the packer 40 depicted in FIG. 4 isillustrative, and alternative embodiments having other mechanicalfeatures providing the same functional needs of a packer (i.e., fluidlyisolating and sealing one casing section from another casing section ina well, and in the case of a controllable packer, regulating andcontrolling fluid flow between these isolated casing sections) arepossible and encompassed within the present invention. For instance, theinlet and outlet ports 90, 92 may be exchanged to pass fluids from theannular space 94 above the packer 40 to the space 96 below the packer.Also, the communications and control module 84 and the bypass controlvalve 44 may be located in upper portion of the packer 40, above theslips 28. The controllable packer 40 may also comprise sensors (notshown) electrically connected to or within the communication and controlmodule 84, to measure pressures or temperatures in the annuli 94, 96 orwithin the production tubing 24. Hence, the measurements can betransmitted to the computer system 56 at the surface 54 using thecommunications and control module 84, providing real time data ondownhole conditions. Also the setting and unsetting mechanism of thepacker slips may be actuated by one or more motors driven and controlledby power and commands received by module 84.

[0051] In other possible embodiments of the present invention, theelectrically powered device 42 of the packer 40 may comprise: a modem86; a sensor (not shown); a microprocessor (not shown); a packer valve44; a tracer injection module (not shown); an electrically controllablegas-lift valve (e.g., for controlling the flow of gas from the annulusto inside the tubing) (not shown); a tubing valve (e.g., for varying theflow of a tubing section, such as an application having multiplebranches or laterals) (not shown); a communications and control module84; a logic circuit (not shown); a relay modem (not shown); otherelectronic components as needed (not shown); or any combination thereof.

[0052] Also in other possible embodiments of the present invention,there may be multiple controllable packers and/or multiple inductionchokes. In an application where there are multiple controllable packersor additional conventional packers combined with the present invention,it may be necessary to electrically insulate some or all of the packersso that a packer does not act as a short between the piping structure(e.g., tubing 24) and the electrical return (e.g., casing 22) where sucha short is not desired. Such electrical insulation of a packer may beachieved in various ways apparent to one of ordinary skill in the art,including (but not limited to): an insulating sleeve about the tubing atthe packer location; a rubber or urethane portion at the radial extentof the packer slips; an insulating coating on the tubing at the packerlocation; forming the slips from non-electrically-conductive materials;other known insulating means; or any combination thereof. The presentinvention also can be applied to other types of wells (other thanpetroleum wells), such as a water well.

[0053] It will be appreciated by those skilled in the art having thebenefit of this disclosure that this invention provides a packercomprising an electrically powered device, as well as a petroleumproduction well incorporating such a packer. It should be understoodthat the drawings and detailed description herein are to be regarded inan illustrative rather than a restrictive manner, and are not intendedto limit the invention to the particular forms and examples disclosed.On the contrary, the invention includes any further modifications,changes, rearrangements, substitutions, alternatives, design choices,and embodiments apparent to those of ordinary skill in the art, withoutdeparting from the spirit and scope of this invention, as defined by thefollowing claims. Thus, it is intended that the following claims beinterpreted to embrace all such further modifications, changes,rearrangements, substitutions, alternatives, design choices, andembodiments.

The invention claimed is:
 1. A packer adapted for use in a well, saidpacker including an electrically powered device adapted for receiving ACpower from the surface using at least one of the tubing or casing as aconductor.
 2. A packer in accordance with claim 1, wherein saidelectrically powered device comprises an electrically controllable valveadapted to control fluid communication from one side of said packer toanother side of said packer.
 3. A packer in accordance with claim 2,wherein said electrically powered device further comprises acommunications and control module being electrically connected to saidelectrically controllable valve, said module comprising a modem adaptedto receive control commands encoded within communication signals, andsaid module being adapted to decode said control commands received bysaid modem and control the movement of said valve using said controlcommands when said packer is operably installed.
 4. A packer inaccordance with claim 1, wherein said electrically powered devicecomprises: a sensor adapted to detect at least one physicalcharacteristic of a surrounding environment and generate datacorresponding to said physical characteristic; and a modem adapted toreceive said data from said sensor and electrically transmit said datain the form of an electrical communication signal.
 5. A petroleum wellfor producing petroleum products, comprising: a piping structurecomprising an electrically conductive portion extending along at leastpart of said piping structure; a source of time-varying currentelectrically connected to said electrically conductive portion of saidpiping structure; an electrical return; and a packer including anelectrically powered device, said electrically powered device beingelectrically connected potential such that part of said time-varyingcurrent is routed through said device when said time-varying current isapplied through said electrically conductive portion of said pipingstructure.
 6. A petroleum well in accordance with claim 5, wherein saidelectrically powered device comprises an electrically controllable valveadapted to control fluid communication between one side of said packerand another side of said packer when said packer is operably installed.7. A petroleum well in accordance with claim 5, wherein saidelectrically powered device comprises a sensor adapted to measure aphysical quantity.
 8. A petroleum well in accordance with claim 5,wherein said electrically powered device comprises a modem adapted tosend and receive communications along said electrically conductiveportion of piping structure.
 9. A petroleum well in accordance withclaim 5, wherein said electrically powered device comprises a chemicalinjection module adapted to controllably inject a substance into a flowstream.
 10. A petroleum well in accordance with claim 5, wherein saidelectrically powered device comprises an electrically controllable valveadapted to control fluid communication between an exterior and aninterior of a production tubing string.
 11. A petroleum well inaccordance with claim 5, wherein said electrically powered devicecomprises an electrically controllable valve adapted to control fluidflow within a production tube.
 12. A petroleum well in accordance withclaim 5, wherein said piping structure comprises a production tubingstring of said well.
 13. A petroleum well in accordance with claim 5,wherein said piping structure comprises a well casing of said well. 14.A petroleum well in accordance with claim 5, wherein said electricalreturn comprises a well casing of said well.
 15. A petroleum well inaccordance with claim 5, wherein said electrical return comprises atleast a portion of an earthen ground.
 16. A petroleum well in accordancewith claim 5, further comprising a second induction choke, said secondinduction choke being located about another part of said electricallyconductive portion of said piping structure and at a location along saidpiping structure such that said electrical connection location for saidtime-varying current source is located between said induction chokes.17. A petroleum well in accordance with claim 5, further comprising asecond packer.
 18. A petroleum well in accordance with claim 17, whereinsaid second packer comprises an electrical insulator so that saidelectrically conductive portion of said piping structure is notelectrically connected to said electrical return at said second packerwhen said second packer is operably installed.
 19. A petroleum well inaccordance with claim 17, wherein said second packer is part of saidelectrical return.
 20. A petroleum well in accordance with claim 5,wherein said packer is located on said source-side of said inductionchoke.
 21. A petroleum well in accordance with claim 5, wherein saidpacker is located on said electrical-return-side of said inductionchoke.
 22. A method of operating a petroleum well comprising: providingan electrically powered packer in a petroleum well; providing a pipingstructure in said well, said piping structure comprising an electricallyconductive portion extending along at least part of said pipingstructure; operably installing said electrically powered packer in saidwell, said electrically powered packer comprising an electricallypowered device, such that said device is electrically connected to saidelectrically conductive portion of said piping structure when said wellis operable for petroleum production; operably installing an inductionchoke about part of said electrically conductive portion of said pipingstructure; supplying time-varying current to said piping structure;routing part of said time-varying current through said electricallypowered device using said induction choke; and producing petroleumproducts with said well.
 23. A method in accordance with claim 22,further comprising the steps of: measuring a physical quantity with saidelectrically powered device, wherein said electrically powered devicecomprises a sensor; and varying a flow of petroleum products in saidwell based on said measurements.
 24. A method in accordance with claim22, further comprising the step of: electrically controlling fluidcommunication between sections of said well using said packer, whereinsaid electrically powered device comprises an electrically controllablevalve.